Op 30-3-2012 12:17, Pierpaolo Bernardi schreef:
> On Fri, Mar 30, 2012 at 11:53, Roelof Wobben<r.wobben at home.nl> wrote:
>> Op 30-3-2012 9:46, Pierpaolo Bernardi schreef:
>>>>> Hello Roelof,
>>>>>> On Fri, Mar 30, 2012 at 09:32, Roelof Wobben<r.wobben at home.nl> wrote:
>>>>>>> (define (show-ufo ufo)
>>>> (place-image BLU (ufo-loc u) MTS))
>>>>>>>> But still I can't get the show-ufo work.
>>> Check carefully the name of your variables!
>>>>>> Doesn't DrRacket give you an explicative error message in this case?
>>>>>> P.
>>>>> Oke, I will do that.
>>>> Yes, The error that variable u is not known.
> I didn't want to tease you. I thought that you would see it if I
> pointed you at it. 8^)
>> (define (show-ufo ufo)
> (place-image BLU (ufo-loc u) MTS))
>> See that the variables ufo and u should actually the same variable.
> So, either you rename u to ufo, or rename ufo to u.
>> There may be other errors, I have not checked further.
>> Cheers
> P.
>>>>>>> Roelof
>>>> ____________________
>> Racket Users list:
>>http://lists.racket-lang.org/users
Are you sure ?
I thought that the position of the ufo can be find at (posn-y p) and
(posn-x) because the postition is a struct of Posn.
Roelof